The present invention concerns methods and apparatus for evaluating and treating poultry eggs, and, in particular, concerns methods and apparatus for non-invasively candling poultry eggs to determine the conditions of the eggs and to handle and treat the eggs in accordance with such determination.
Discrimination between poultry eggs on the basis of some observable quality is a well-known and long-used practice in the poultry industry. xe2x80x9cCandlingxe2x80x9d is a common name for one such technique, a term which has its roots in the original practice of inspecting an egg using the light from a candle. As is known to those familiar with poultry eggs, although egg shells appear opaque under most lighting conditions, they are in reality somewhat translucent, and when placed in front of a direct light, the contents of the egg can be observed.
In most practices, the purpose of inspecting eggs, particularly xe2x80x9ctable eggsxe2x80x9d for human consumption, is to identify and then segregate those eggs which have a significant quantity of blood present, such eggs themselves sometimes being referred to as xe2x80x9cbloodsxe2x80x9d or xe2x80x9cblood eggs.xe2x80x9d These eggs are less than desirable from a consumer standpoint, making removal of them from any given group of eggs economically desirable.
U.S. Pat. Nos. 4,955,728 and 4,914,672, both to Hebrank, describe a candling apparatus that uses infrared detectors and the infrared radiation emitted from an egg to distinguish live from infertile eggs.
U.S. Pat. No. 4,671,652 to van Asselt et al. describes a candling apparatus in which a plurality of light sources and corresponding light detectors are mounted in an array, and the eggs passed on a flat between the light sources and the light detectors.
In many instances it is desirable to introduce a substance, via in ovo injection, into a living egg prior to hatch. Injections of various substances into avian eggs are employed in the commercial poultry industry to decrease post-hatch mortality rates or increase the growth rates of the hatched bird. Similarly, the injection of virus into live eggs is utilized to propagate virus for use in vaccines. Examples of substances that have been used for, or proposed for, in ovo injection include vaccines, antibiotics and vitamins. Examples of in ovo treatment substances and methods of in ovo injection are described in U.S. Pat. No. 4,458,630 to Sharma et al. and U.S. Pat. No. 5,028,421 to Fredericksen et al., the contents of which are hereby incorporated by reference as if recited in full herein. The selection of both the site and time of injection treatment can also impact the effectiveness of the injected substance, as well as the mortality rate of the injected eggs or treated embryos. See, e.g., U.S. Pat. No. 4,458,630 to Sharma et al., U.S. Pat. No. 4,681,063 to Hebrank, and U.S. Pat. No. 5,158,038 to Sheeks et al. U.S. Patents cited herein are hereby incorporated by reference herein in their entireties.
In ovo injections of substances typically occur by piercing the egg shell to create a hole through the egg shell (e.g., using a punch or drill), extending an injection needle through the hole and into the interior of the egg (and in some cases into the avian embryo contained therein), and injecting the treatment substance through the needle. An example of an injection device designed to inject through the large end of an avian egg is disclosed in U.S. Pat. No. 4,681,063 to Hebrank; this device positions an egg and an injection needle in a fixed relationship to each other, and is designed for the high-speed automated injection of a plurality of eggs. Alternatively, U.S. Pat. No. 4,458,630 to Sharma et al. describes a bottom (small end) injection machine.
In commercial poultry production, only about 50% to 90% of commercial broiler eggs hatch. Eggs that do not hatch include eggs that were not fertilized (which may include rots), as well as fertilized eggs that have died (often classified into early deads, mid-deads, rots, and late deads). Infertile eggs may comprise from about 5% up to about 25% of all eggs set. Due to the number of dead and infertile eggs encountered in commercial poultry production, the increasing use of automated methods for in ovo injection, and the cost of treatment substances, an automated method for identifying, in a plurality of eggs, those eggs that are suitable for injection and selectively injecting only those eggs identified as suitable, is desirable.
U.S. Pat. No. 3,616,262 to Coady et al. discloses a conveying apparatus for eggs that includes a candling station and an inoculation station. At the candling station, light is projected through the eggs and assessed by a human operator, who marks any eggs considered non-viable. Non-viable eggs are manually removed before the eggs are conveyed to the inoculating station.
According to embodiments of the present invention, a method for classifying poultry eggs includes providing a plurality of eggs each having a respective physical egg location, measuring the opacities of the eggs, measuring the temperatures of the eggs, and classifying the eggs as a function of the opacities and the temperatures of the eggs. The step of classifying includes identifying clear eggs of the plurality of eggs using the opacities of the eggs, determining a spatial temperature trend among the plurality of eggs using the identification of the clear eggs, and identifying live eggs of the plurality of eggs using the spatial temperature trend.
Preferably, the step of determining a spatial temperature trend includes generating a temperature trend map including a predicted egg temperature for each egg location. The step of identifying the live eggs may include comparing the measured temperatures and the predicted temperatures.
The step of classifying may include correcting the egg temperatures for relative egg locations using the identification of the clear eggs, and identifying live eggs of the plurality of eggs using the corrected egg temperatures. The step of identifying live eggs may include determining a threshold temperature, comparing the corrected egg temperatures to the threshold temperature, and classifying the eggs having a corrected egg temperature greater than the threshold temperature as live.
The method may include identifying upside-down eggs and excluding the temperatures of the upside-down eggs from the temperature trend determination.
According to further embodiments of the present invention, a method for classifying poultry eggs includes measuring the opacities of the eggs, measuring the temperatures of the eggs, and classifying the eggs as a function of the opacities and the temperatures of the eggs. The step of classifying includes identifying clear eggs of the plurality of eggs using the opacities of the eggs, and identifying live eggs of the plurality of eggs using the temperatures of the eggs. The step of identifying live eggs is facilitated by the identification of the clear eggs.
The step of classifying may include identifying a remaining group of the eggs, the remaining group not including the clear eggs, and identifying live eggs in the remaining group using the temperatures of the eggs of the remaining group and not the temperatures of the clear eggs. The method may further include identifying at least one other class of non-live eggs, preferably early dead eggs. The eggs may be physically separated into at least three groups including a live egg group, a clear egg group, and a non-live and non-clear egg group.
According to other embodiments of the present invention, an apparatus for classifying a plurality of poultry eggs each having an opacity and a temperature includes means for detecting the opacities of the eggs, means for detecting the temperatures of the eggs, and means for classifying the eggs using the opacities and the temperatures of the eggs. The means for classifying identifies clear eggs of the plurality of eggs using the opacities of the eggs, and identifies live eggs of the plurality of eggs using the temperatures of the eggs. The identification of live eggs is facilitated by the identification of the clear eggs.
The means for classifying may correct the egg temperatures for relative egg locations using the identification of the clear eggs, and identify live eggs of the plurality of eggs using the corrected egg temperatures. The means for classifying may identify a remaining group of the eggs, the remaining group not including the clear eggs, and identify live eggs in the remaining group using the temperatures of the eggs of the remaining group and not the temperatures of the clear eggs. The means for classifying may identify at least one other class of non-live eggs, preferably early dead eggs. The apparatus may include an injector operative to inject live eggs with a treatment substance.
Preferably, the means for detecting the opacities of the eggs includes a light candling system which detects the opacities of the eggs and generates opacity signals corresponding to the egg opacities, the means for detecting the temperatures of the eggs includes a thermal candling system which detects the temperatures of the eggs and generates temperature signals corresponding to the egg temperatures, and the means for classifying the eggs includes a controller which receives the opacity and temperature signals and classifies the eggs as a function of the opacities and temperatures of the eggs, the controller being operative to selectively generate a control signal based on the egg classifications. The light candling system may comprise an infrared emitter and an infrared detector, and the thermal candling system may comprise an infrared sensor.
According to further embodiments of the present invention, a method for classifying poultry eggs includes providing a plurality of eggs each having a respective physical egg location, measuring the temperatures of the eggs, and classifying the eggs as a function of the temperatures of the eggs. The step of classifying includes determining a spatial temperature trend among the plurality of eggs, and identifying live eggs of the plurality of eggs using the spatial temperature trend.
The step of determining a spatial temperature trend may include generating a temperature trend map including a predicted egg temperature for each egg location. The step of classifying may include correcting the egg temperatures for relative egg locations, and identifying live eggs of the plurality of eggs using the corrected egg temperatures.
Objects of the present invention will be appreciated by those of ordinary skill in the art from a reading of the Figures and the detailed description of the preferred embodiments which follow, such description being merely illustrative of the present invention.